Coinfection

HIV-positive people with hepatitis B virus (HBV) coinfection had impaired CD4 cell recovery after starting antiretroviral (ART) and a higher risk of death than those without hepatitis B, but use of ART regimens containing tenofovir significantly reduced mortality, according to a study presented at the recent Conference on Retroviruses and Opportunistic Infections (CROI 2016)in Boston.

Hepatitis B coinfection is common among people with HIV in sub-Saharan Africa. HIV/HBV coinfection is associated with impaired immunological recovery and worse clinical outcomes -- even among people on effective ART -- but the association between coinfection and mortality, and the effect of tenofovir (Viread, also in Truvada and single-tablet regimens such as Atripla) is not fully understood.

Murithi Mbae from the London School of Hygiene and Tropical Medicine and colleagues conducted a retrospective analysis of data from the African Infectious Disease Village Clinics in the Rift Valley province of Kenya to determine the prevalence of hepatitis B among HIV-positive patients enrolling in ART programs between 2003-2012. The clinic serves a predominantly rural Maasai population of approximately 200,000 people. This cohort enrolled 7155 patients followed for a total of 12,408 person years.

All participants were screened for hepatitis B surface antigen (HBsAg) at baseline, which indicates current HBV infection. ART was prescribed according to WHO and Kenyan guidelines, with an initiation threshold of <200 cells/mm3 until 2007, increased to 250 during 2007-2010 and 350 thereafter. First-line ART consisted of stavudine (d4T, Zerit) or zidovudine (AZT, Retrovir) plus lamivudine (3TC, Epivir) with efavirenz (Sustiva or Stocrin) or nevirapine (Viramune) until 2010, when tenofovir was introduced. A total of 6214 people started ART, of whom 3125 used tenofovir-containing regimens.

Patients were monitored every 3 months for a mean duration of approximately 1.75 years. The researchers compared clinical outcomes and immunological and virological response to ART between HIV monoinfected and HIV/HBV coinfected participants. The impact of tenofovir-containing ART was determined in an analysis adjusting for age, sex, baseline CD4 count, calendar year, and baseline creatinine level.

Results

HBsAg was detected in 451 patients, for a prevalence of 6.3%; HBsAg prevalence was significantly higher among men than among women (9.2% vs 5.0%) and increased with age.

Based on these findings, they cautioned, "Any move away from tenofovir-containing first-line ART in sub-Saharan Africa must be combined with hepatitis B surface antigen screening to enable effective treatment of individuals with HIV/HBV coinfection."